from the designer's announcement:
Yes, there is a DINO-PIRATES OF NINJA ISLAND version of Old School Hack now available. Choose from the Swashbuckler, the Sea Dog, the Ninja Shadow, the Ninja Sword, the Shaman, the Hunter and the Sorcerer -- all with their own powers and abilities. Imperials, DINO-PIRATES, ninjas and natives all in the mix. We tweaked the armor rules a bit, since heroes in DINO-PIRATES OF NINJA ISLAND are more swashbuckly, less clompy and stompy.
The DINO-PIRATES OF NINJA ISLAND setting isn't tied to a particular mechanic, and the rules aren't meant to model physical laws. Rather, the rules (both the "classic" DINO-PIRATES and these Old School rules) are meant to provide a structure in which interesting stories are likely to happen. So why not supply multiple rulesets? If you like one more than the other, that doesn't make you a bad person. Try 'em both!
All you need to do is download the original Old School Hack rules from Kirin's site, then download the DPoNI substitution for the DINO-PIRATE-y classes and abilities. Then yaaaarrrrr! You're ready for adventure among the islands!
This initial version of the DPoNI OSH rules has no art, except the DPoNI logo, and depends on the Old School Hack rules for additional information.